German Patent Application No. P 41 41 546.9 teaches an electromagnetic valve (for controlling pressure fluid flow), that includes a valve seat member firmly caulked within a valve supporting member, wherein the valve seat member comprises a diaphragm bore. The valve seat member, prior to final valve assembly, is placed into the bore section of a valve support member so that the adjustment of the valve seat member (oriented by the tolerances of the individual components) cannot be effected. The valve seat member is positioned to conform to the shape of the bore step and is held in caulked position. Moreover, the electromagnetic valve described in the afore-mentioned patent application has the disadvantage that, as a result of the limited structural volume available, no provision is made for the integration in the valve support member of a check valve which is a common requirement for hydraulic braking systems having a slip control. A further disadvantage is found in the aforementioned valve inasmuch as the diaphragm bore with the valve seat member forms a unit caulked within the valve support member, no individual adjustment of the diaphragm can be performed.
It is, therefore, the object of the invention to provide an easy-to-manufacture electromagnetic valve enabling, by simple means, a precise adjustment of the axial air gap required between the magnetic core and the hold-on magnet and permitting customs selection of the diaphragm member without requiring any substantial modification of the electromagnetic valve.
These objects, in the practice of the invention, have been fulfilled by the present invention which includes a valve seat member that is coaxially displaceable with respect to a valve needle, thereby providing in a simple manner, through a corresponding design of the valve support member and the valve seat member, a versatile and compact electromagnetic valve.
Advantageous embodiments of the invention are hereinafter described and explained in closer detail in connection with additional features and advantages of the invention and with reference to the drawings, a brief description of which follows.